Visual Phasing usually involves having three siblings, their DNA, and comparing it to
each other to identify which segments came from which grandparent. Now, many people have asked,
well can you do Visual Phasing with two siblings instead of three siblings? And the answer is,
yeah. It's a little bit different process, but we're gonna go over it today. Howdy! Welcome to
Family History Fanatics, where we love helping you climb your family tree and have fun along the way.
There are some differences with Visual Phasing with two siblings as opposed to three siblings.
And it mainly has to do with assigning Recombination Points and figuring out what
those segments are you need to start with matches. If you don't know how some of your matches are
related to those two siblings, then you're not going to be able to do Visual Phasing with it. But
let's go through the process step by step and see how you can do this with just two siblings. Now,
the First Step is you need two siblings' data. And right now, it needs to be uploaded to GEDmatch so
that you can actually see both the Half Identical Regions as well as the Fully Identical Regions.
So, if you haven't uploaded your sibling data to GEDmatch, then do that. Now, now the First
Principle to remember throughout this is that each chromosome is separate and unrelated to others.
You can't use the data from one chromosome to try to fill in information on another chromosome. You
have to think of this as really 22 separate projects that you're doing for the 22 separate
autosomal chromosome pairs. Now, Step Two, after you have everything uploaded to GEDmatch,
is you want to use the One-to-One Comparison to get the graphics. And in this case, since you
only have two people, you only really need the one graphic for each one of those chromosomes.
whereas when we had three people, we needed three different graphics to get all the comparisons.
So, here is my graphics of my two people. Person A and Person B. what we've done is we've taken
and blown them up a little bit, so they're easier to see. But you have both the yellow-green-red on
the top and then the blue-black on the bottom. So, let's go over these color regions and what they
mean. Now, the first one is if you have a solid green area, and then there's blue underneath it.
That indicates a Fully Matched Region - a Fully Identical Region (FIR). And that's
basically where both siblings receive the same DNA from both of their parents. The next is the
yellow and usually with some little bits of green interspersed and then blue underneath. And this is
the Half Matched Region or Half Identical Region (HIR). In other words, they each got the same DNA
from one of their parents in these locations. And finally, there is wherever you have some red, and
there's usually some yellow mixed in with it, and sometimes there might be a stripe of green or so,
and then it's going to be black underneath. This indicates that it is Not A Match. In other words,
they receive different DNA from both of their parents. And so that's why they're not matching
for that. Now, Principle Number Two is is that as the color regions change, these are
the Recombination Points. And you can see I've highlighted them here. There's one, two, three,
four, five, six, seven Recombination Points on this chromosome. Now, when you think about this,
each person has two chromosomes- a pair. And there's two people. So,
while there's seven Recombination Points in the comparison,
well, those seven Recombination Points are distributed just between these four chromosomes.
So, it's entirely possible that one or more of those chromosomes have no Recombination Points.
And the others have three or four. we'll see as we get some more data. Another Principle Three to be
concerned with is that a Fully Matched Region, remember the solid green, it cannot be adjacent to
a No-Match Region, which would be the red with the black. So, there's always going to be a Half-Match
region in between a Fully Matched Region and a No-Match Region. And that's just something to be
aware of. It usually only comes up in a couple of places but just keep that in your mind. All right.
So, Step Three. Now, we've downloaded our data. We have it in. You know, a Word file, a spreadsheet.
However, you want to do it. We're going to draw our recombination lines. Remember, we
identified our Recombination Points is where the color changes. And so we're simply going
to draw some lines. Now, of those Recombination Points, and this is going to help us to build out
the different chromosomes later well, Principle Four is that every chromosome pair has a maternal
and a paternal chromosome. So, you get one chromosome from your mother, and you get one
chromosome from your father. Recombination Points usually don't happen at the exact same place on
those two chromosomes. They might happen really close together by chance, but they don't happen
in the exact same place. And so we want to make it a goal to identify which ones are the paternal
and which ones are the maternal chromosomes all right so. Now, we go on to Step Four. And since
each person has two chromosomes for this pair, we want to create a graphic of the two chromosomes
for each person. And this is just really easy as far as having a box with two stacked chromosomes
underneath this. And so you can see with the lines identifying the Recombination Points, we've
actually separated out these chromosomes into potential segments. Now, I say potential segments
because each one of these chromosomes does not have all of these Recombination Points. Before we
continue, if you want to support our work, there's many ways that you can help. In the description
below, there are links to our show notes, to free guides, as well as our website and blog.
However, the most important thing you can do is leave a comment and share this video with
your friends. we continue to grow thanks to viewers like you. Now, Principle Five,
each chromosome is made up of grandmother and grandfather segments. And that's the whole goal
of Visual Phasing is to divide up the chromosomes into which parts came from which grandparent. So,
the maternal chromosome is made up of your maternal grandfather and grandmother's segments.
And the same with your paternal chromosome. You don't have a chromosome that is partly a maternal
grandmother and partly a paternal grandmother. That just can't happen. But each chromosome is
going to have these segments. unless, of course, it is all from a grandfather or all from a
grandmother. Now, Principle Six is that these segments only switch colors at a Recombination
Point for that person. Now, we've already pointed out that these Recombination Points
are discrete in that they almost never happen in more than one chromosome at a time. So, as
we're going through, whenever we identify where a Recombination Point is on a particular chromosome,
we know that none of the other chromosomes have that Recombination Point. So, with the data that
we have, we want some sort of a starting point. And I'm going to use the largest No-Match or
Fully Identical Region because that will give us information on a place of both people. Now,
this is different from where we then start with three siblings because we have more data with
three siblings. So, we're actually skipping over a bunch of steps with three siblings and just
looking at these two siblings. So, we're going to color the largest one. Now, just looking at this.
This is the largest section. I'm going to color it with four distinct colors here because this
is a No-Match region. So, they don't match each other. So, for Person A, I have maroon and teal.
And for Person B, I have orange and purple. And what this means is is that maroon and orange go
together as either the maternal or the paternal. we don't know yet. And teal and purple go together
as either the maternal or the paternal. Again we don't know yet. So, we've just colored the largest
segment that we could that gives us information on both people. So, then we go
to our next step is. we want to use matches with known relationships to identify our segments.
So, let's take a look at a match. And what I've done is I've put it just underneath each one
of these chromosomes. So, this is a match to a grandparent, which is a Hankinson grandparent.
And we have underneath a how the match looks there. And we have underneath B
how the match looks there. what we can see is that this blue area actually covers this part
all right in here. Now, we have two colors there. One of those colors has to be a Hankinson. And
in this case, since we've not assigned any labels to any of these, we can choose whichever color we
want to be Hankinson. So, in this case, I'm going to call the teal my Hankinson. And because
remember, we have each chromosome is grandparent and grandmother, I can then label purple,
which is connected with Hankinson as the other grandparent. In this case, that would be Brown.
So, I've identified Hankinson and Brown in this part. Now, I happen to know that these are on
the maternal side. So, I know that this bottom chromosome for each one of these is the maternal
chromosome, which means the top one is the paternal chromosome. Although I haven't identified
the names of the segments yet. Then I also want to extend the segments and add any new segments
as needed. So, let's take a look here. So, we've already shown that this blue,
that matches well, that's going to be able to extend all the way here. And actually,
extend a little bit right there. Likewise, we know that, hey, this is a Hankinson match. So,
these sections right here are going to be able to be labeled as Hankinson. And these sections
right here are going to be able to be labeled as a Hankinson. Now because. And this is a
key of thinking about this logically. Because there was Not A Match over here,
I can actually label that end segment as a Brown. It's a No-Match region. And I can also label this
segment here as a Brown because it is also a No-Match region. So, I've actually expanded
this maternal chromosome into a lot of areas now with just one match. So, the next step is then to
identify our Recombination Points. Now, remember a Recombination Point occurs when there is a color
change, and that's what we're looking for on these grandparent segments is. where do the grandparents
change? As we're looking at this, we can see that on B, we have a grandparent change right there.
And so I've labeled that as a B Recombination Point. we can also see that we have
on a A grandparent change right there. And so that one has been labeled as A Recombination Point. So
now that we have labeled our Recombination Points, we can go through, and we can extend
segments across our Recombination Points. Well, here we know that this line right here is B.
And this line right here is A. But it's already accounted for down here. So, we're able to extend
this maroon all the way over to the end because we've already accounted for our two Recombination
Points. And likewise, we can extend the orange all the way over to our end. Now,
remember the maroon and the orange here represent our paternal chromosomes. we don't know which one
is which grandparent yet. But because of the rules of Visual Phasing, we're able to start to identify
for the fuller what segments are being contained with these. So, let's look at Step Number Ten.
We want to, Now, just repeat steps number six to nine with other matches. In other words,
we want to try to gather more matches and see how we can go through and paint stuff. So, let's use
a different match here. This is going to be a Geiszler match. Now, this match only matched
Person A. They didn't match Person B. And you might think. Well, that's not very good. But let's
see what kind of data we can get from this. Now, we know that this is a paternal match. So, we're
going to be looking at the maroon and orange lines right here. And as we're looking at this line,
we can see that, hey, this covers this area right in here. we already know that part of this
is maroon. And so, that match is going to be Geiszler. That maroon is going to be Geiszler. So,
what I've done is I've gone through, and I've extended that out. So, it covers the whole
segment up to the next Recombination Point. And I've labeled it as Geiszler. Now, that also means
that the one down below is going to be Zumstein, which is the other grandparent on the paternal
side. Now, we don't know too much more. But what we do know is that this is a Fully Matched Region
right here, which means that this right here in this little segment is going to have to be that
Geiszler- that maroon one. Other thing that we can also see here is that on this Recombination Point,
there is no recombination on Person A. So, that means that that is going to have to be
a Person B recombination. Now, we don't know which one is changing yet, but we know that
that is going to be B. So, I've labeled that B right. Now, let's do another match. And this
is a Brown match. So, we're looking back at the maternal chromosome again. And we can see that
we have this area that both of them match the exact same, and it is in this area right here.
we know that that is going to be a Brown. Now, in this case, because this is a Half Matched Area,
that means they're going to have different colors on the paternal side. Because they're both going
to have Browns right in this area. So, let's color this as a Brown. And that actually makes a nice
large segment there for us. Now, because we don't have any data yet on the paternal side of that,
we can't color the top of that just yet. But we can go through, and we can identify, now, another
Recombination Point. Because we see this Hankinson changing to Brown, and that's going to mean that
we are going to say that, hey, this is another Recombination Point. So, far we have quite a bit
of this solved. And here's the amazing thing! we've looked at three matches. So far,
just three matches for this one chromosome. Now, you're going to be doing this for
all 22 chromosomes, but we've identified four of our seven Recombination Points, more than half of
them. And if you look at the colors, we've got roughly about 65% of all the segments assigned
to a grandparent, which is pretty great. So, you might be able to find another couple of segments
if you can find another Zumstein and a Geiszler that fits in the first half of those chromosomes.
And you're going to have this chromosome almost completely identified with just a few
segments. And that is how you do Visual Phasing with just two people. It is again a little bit
different in that we're relying mainly on our matches to identify and assign those segments. But
it is with a handful of matches you can actually get most of the chromosome identified. And again,
going through 22 chromosomes for each of these. It's actually. You'll be amazed at how much you
can actually identify with just a few matches. And as you're finding more and more matches,
you can be able to solve almost all of these 22 chromosomes. So, if you would like to watch the
Visual Phasing series, you can start with this video up top here. But if you want to
learn something else about DNA, then try this video down below. I just recorded everything
using the streaming button rather than the record button, So now, I have to do it all over again.